Question

1.A gas is stored under 2 atm,what is the final volume of a gas if the pressure was halved under constant temperature?
2.Calculate the density of SO2 gas at STP.
3 calculate the density of CH4 gas at 1.5 atm and 15 degree Celsius.

Answer 1

1. given that P₁= 2atm, P₂= 1 atm( half of P1), volume at 1atm of any gas V₁ = 22.4 L, v₂=?

from the gas law P₁V₁/T₁= P₂V₂/T₂  when T is constant P₁V₁=P₂V₂

V₂= 1*22.4/2= 11.2 L

2. the volume of any gas at STP= 22.4 L, and the molecular mass of SO₂= 64g/mol

now the density of SO₂= mass/ volume = 64/22.4= 2.857g/ml

3. density D= PM/RT where T= 15+273= 288K, R= 0.0821, P= 1.5 atm, M of CH₄= 16.04g/mol

by sustituting these values in above equation density of CH₄= (1.5*16.04)/0.0821*288

= 24.06/23.644= 1.017 g/ml